The Birth of Banking (IV) - Practice of Fractional Reserve

To understand the power of these three innovations, first-year MBA students at Harvard Business School play a simplified money game. It begins with a notional central bank paying the professor $100 on behalf of the government, for which he has done some not very lucrative consulting. The professor takes the banknotes to a bank notionally operated by one of his students and deposits them there, receiving a deposit slip. Assuming, for the sake of simplicity, that this bank operates a 10 per cent reserve ratio (that is, it wishes to maintain the ratio of its reserves to its total liabilities at 10 per cent), it deposits $ 10 with the central bank and lends the other $90 to one of its clients. While the client decides what to do with his loan, he deposits the money in another bank. This bank also has a 10 per cent reserve rule, so it deposit $9 at the central bank and lends out the remaining $81 to another of its clients. After several more rounds, the professor asks the class to compute the increase in the supply of money. This allows him to introduce two of the core definitions of modern monetary theory: M0 (also known as the monetary base or high-powered money), which is equal to the total liabilities of the central bank, that is, cash plus the reserves of private sector banks on deposit at the central bank; and M1 (also known as narrow money), which is equal to cash in circulation plus demand or 'sight' deposits. By the time money has been deposited at three different student banks, M0 is equal to $100 but M1 is equal to $ 271 ($100 + $90 + $81), neatly illustrating, albeit in a highly simplified way, how modern fractional reserve banking allows the creation of credit and hence of money.



The professor then springs a surprise on the first student by asking for his $100 back. The student has to draw on his reserves and call in his loan to the second student, setting off a domino effect that causes M1 to contract as swiftly as it expanded. This illustrates the danger of a bank run. Since the first bank had only one depositor, his attempted withdrawal constituted a call ten times larger than its reserves. The survival of the first banker clearly depended on his being able to call in the loan he had made to his client, who in turn had to withdraw all of his deposit from the second bank, and so on. When making their loans, the bankers should have thought more carefully about how easily they could call back the money - essentially a question about the liquidity of the loan.

Definitions of the money supply have, it must be acknowledged, a somewhat arbitrary quality. Some measures of M1 included travellers' cheques in the total. M2 adds savings accounts, money market deposit accounts and certificates of deposit. M3 is broader still, including eurodollar deposits held in offshore markets, and repurchase agreements between banks and other financial intermediaries. The technicalities need not detain us here. The important point to grasp is that with the spread throughout the Western world of a) cashless intra-bank and interbank transactions b) fractional reserve banking and c) central bank monopolies on note issue, the very nature of money evolved in a profoundly important way. No longer was money to be understood, as the Spaniards had understood it in the sixteenth century, as precious metal that had been dug up, melted down and minted into coins. Now money represented the sum total of specific liabilities (deposits and reserves) incurred by banks.

Credit was, quite simply, the total of banks' assets (loans). Some of this money might indeed still consist of precious metal, though a rising proportion of that would be held in the central bank's vault. But most of it would be made up of those banknotes and token coins recognized as legal tender along with the invisible money that existed only in deposit account statements. Financial innovation had taken the inert silver of Potosi and turned it into the basis for a modern monetary system, with relationships between debtors and creditors brokered or 'intermediated' by increasingly numerous institutions called banks. The core function of these institutions was now information gathering and risk management. Their source of profits lay in maximizing the difference between the costs of their liabilities and the earnings on their assets, without reducing reserves to such an extent that the bank became vulnerable to a run - a crisis of confidence in a bank's ability to satisfy depositors, which leads to escalating withdrawals and ultimately bankruptcy: literally the breaking of the bank.

Significantly, even as Italian banking techniques were being improved in the financial centres of Northern Europe, one country lagged unexpectedly far behind. Cursed with an abundance of precious metal, mighty Spain failed to develop a sophisticated banking system, relying instead on the merchants of Antwerp for short-term cash advances against future silver deliveries. The idea that money was really about credit, not metal, never quite caught on in Madrid. Indeed, the Spanish crown ended up defaulting on all or part of its debt no fewer than fourteen times between 1557 and 1696. With a track record like that, all the silver in Potosi could not make Spain a secure credit risk. In the modern world, power would go to the bankers, not the bankrupts.